JPS6011646Y2 - flat package - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to an integrated circuit package, and in particular a housing whose bottom is made of an insulating material for mounting semiconductor integrated circuit chips, and a housing with semiconductor integrated circuits arranged around the periphery of the bottom of the housing. and a plurality of electrodes for electrically connecting the device to an external circuit.

Such flat packages can be mounted on a thick film integrated circuit board with an electrode pattern deposited or printed on it to form a hybrid integrated circuit, or mounted on a printed circuit board with a circuit pattern printed on it to form an electronic circuit package. It is known to be advantageous in terms of miniaturization, low cost, and productivity.

However, due to the original demand for miniaturization, the spacing between the electrodes of the package is narrow, and the spacing between the bottom of the package and the substrate on which it is mounted is also narrow.

When soldering the package electrodes and the circuit board pattern using flux in the bonding process to mount such a flat package on a circuit board, capillarity occurs in the spacing between these electrodes and the gap between the package and the circuit board. It is difficult to completely remove the excess flux that has entered through the cleaning process.

Such residual flux causes a decrease in the insulation between the electrodes, progression of silver migration in the conductor pattern, and corrosion of the electrodes.

Therefore, such conventional flat packages reduce the reliability of the entire electronic circuit system using them.

The purpose of the present invention is to provide a flat package that can effectively remove such residual flux, thereby increasing the productivity of electronic devices incorporating such a package and improving system reliability. .

For this purpose, the flat package according to the present invention has a structure in which grooves are formed on the bottom of the housing between the plurality of electrodes to separate the electrodes from each other, so that cleaning liquid can easily flow in and out during the cleaning process. has been done.

Next, embodiments of the flat package according to the present invention will be described in detail with reference to the accompanying drawings.

FIG. 1 is a plan view showing the bottom of an embodiment of the flat package according to the present invention, and FIG. 2 is a cross-sectional view taken along the dashed line (■-■) and viewed from the direction of the arrow.

This flat package consists of a housing 10 whose bottom is made of an insulating material and which mounts a semiconductor integrated circuit chip (not shown).
and a cap 1 that hermetically seals it with a glass sealant etc.
2.

A conductive electrode 16 for electrically connecting the semiconductor integrated circuit to an external circuit (not shown) is provided at the periphery of the bottom surface 14.
are arranged, and a groove 18 is formed in the bottom surface 14 of the housing 10 between these electrodes 16 as shown.

In the embodiment of FIG. 2, this groove 18 has a rectangular cross-sectional shape as shown.

When this flat package is mounted on a thick film integrated circuit board or a printed circuit board (not shown) and bonded to a circuit pattern on the board, excess flux that adheres to the package or board can easily fill these grooves 18. It can be completely removed by the cleaning solution flowing in and out of the tank.

3 and 4 show grooves 18A and 1 of other cross-sectional shapes.
8B, the cross sections are semicircular and triangular, respectively.

Note that in these drawings, the size and number of electrodes and grooves are exaggerated with respect to the size of the package for the sake of explanation.

With this configuration, the flat package according to the present invention can effectively remove residual flux during the bonding process, improving the corrosion resistance and insulation properties of electronic devices equipped with it, allowing for compact size and high-density packaging. In addition, a highly reliable system can be provided.

[Brief explanation of drawings]

Fig. 1 is a plan view showing the bottom of an embodiment of the flat package according to the present invention, Fig. 2 is a sectional view taken along the dashed line ■-H of the flat package shown in Fig. 1, and Figs. FIG. 6 is a partial cross-sectional view showing another embodiment of the flat package according to the invention. Explanation of symbols of main parts, 10...Housing,
14... bottom surface, 16... electrode, 18...
·····groove.

Claims (1)

[Scope of utility model registration request] A flat package including a housing molded from an insulating material and used to mount a semiconductor integrated circuit chip, and a plurality of electrodes arranged around the periphery of the bottom surface of the housing for electrically connecting the semiconductor integrated circuit to an external circuit. 2. The flat package according to claim 1, wherein a groove is formed on the bottom surface of the housing in the gap between the plurality of electrodes.